7 files changed, 44 insertions, 9 deletions

diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt
index 9164ae3b83bc..9b728dc17535 100644
--- a/Documentation/cachetlb.txt
+++ b/Documentation/cachetlb.txt
@@ -16,7 +16,7 @@ on all processors in the system.  Don't let this scare you into
 thinking SMP cache/tlb flushing must be so inefficient, this is in
 fact an area where many optimizations are possible.  For example,
 if it can be proven that a user address space has never executed
-on a cpu (see vma->cpu_vm_mask), one need not perform a flush
+on a cpu (see mm_cpumask()), one need not perform a flush
 for this address space on that cpu.
 
 First, the TLB flushing interfaces, since they are the simplest.  The
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 998e972f3b1a..30ac65df7d4e 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -110,7 +110,6 @@ static struct mm_struct tboot_mm = {
         .mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
-        .cpu_vm_mask    = CPU_MASK_ALL,
 };
 
 static inline void switch_to_tboot_pt(void)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 201998e5b530..c2f9ea7922f4 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -265,8 +265,6 @@ struct mm_struct {
 
         struct linux_binfmt *binfmt;
 
-        cpumask_t cpu_vm_mask;
-
         /* Architecture-specific MM context */
         mm_context_t context;
 
@@ -316,9 +314,14 @@ struct mm_struct {
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
         pgtable_t pmd_huge_pte; /* protected by page_table_lock */
 #endif
+
+        cpumask_var_t cpu_vm_mask_var;
 };
 
 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
-#define mm_cpumask(mm) (&(mm)->cpu_vm_mask)
+static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
+{
+        return mm->cpu_vm_mask_var;
+}
 
 #endif /* _LINUX_MM_TYPES_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 44b8faaac7c0..f18300eddfcb 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2176,6 +2176,7 @@ static inline void mmdrop(struct mm_struct * mm)
         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
                 __mmdrop(mm);
 }
+extern int mm_init_cpumask(struct mm_struct *mm, struct mm_struct *oldmm);
 
 /* mmput gets rid of the mappings and all user-space */
 extern void mmput(struct mm_struct *);
diff --git a/init/main.c b/init/main.c
index 48df882d51d2..22da33918aef 100644
--- a/init/main.c
+++ b/init/main.c
@@ -509,6 +509,8 @@ asmlinkage void __init start_kernel(void)
         sort_main_extable();
         trap_init();
         mm_init();
+        BUG_ON(mm_init_cpumask(&init_mm, 0));
+
         /*
          * Set up the scheduler prior starting any interrupts (such as the
          * timer interrupt). Full topology setup happens at smp_init()
diff --git a/kernel/fork.c b/kernel/fork.c
index 927692734bcf..8e7e135d0817 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -485,6 +485,20 @@ static void mm_init_aio(struct mm_struct *mm)
 #endif
 }
 
+int mm_init_cpumask(struct mm_struct *mm, struct mm_struct *oldmm)
+{
+#ifdef CONFIG_CPUMASK_OFFSTACK
+        if (!alloc_cpumask_var(&mm->cpu_vm_mask_var, GFP_KERNEL))
+                return -ENOMEM;
+
+        if (oldmm)
+                cpumask_copy(mm_cpumask(mm), mm_cpumask(oldmm));
+        else
+                memset(mm_cpumask(mm), 0, cpumask_size());
+#endif
+        return 0;
+}
+
 static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 {
         atomic_set(&mm->mm_users, 1);
@@ -521,10 +535,20 @@ struct mm_struct * mm_alloc(void)
         struct mm_struct * mm;
 
         mm = allocate_mm();
-        if (mm) {
-                memset(mm, 0, sizeof(*mm));
-                mm = mm_init(mm, current);
+        if (!mm)
+                return NULL;
+
+        memset(mm, 0, sizeof(*mm));
+        mm = mm_init(mm, current);
+        if (!mm)
+                return NULL;
+
+        if (mm_init_cpumask(mm, NULL)) {
+                mm_free_pgd(mm);
+                free_mm(mm);
+                return NULL;
         }
+
         return mm;
 }
 
@@ -536,6 +560,7 @@ struct mm_struct * mm_alloc(void)
 void __mmdrop(struct mm_struct *mm)
 {
         BUG_ON(mm == &init_mm);
+        free_cpumask_var(mm->cpu_vm_mask_var);
         mm_free_pgd(mm);
         destroy_context(mm);
         mmu_notifier_mm_destroy(mm);
@@ -690,6 +715,9 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
         if (!mm_init(mm, tsk))
                 goto fail_nomem;
 
+        if (mm_init_cpumask(mm, oldmm))
+                goto fail_nocpumask;
+
         if (init_new_context(tsk, mm))
                 goto fail_nocontext;
 
@@ -716,6 +744,9 @@ fail_nomem:
         return NULL;
 
 fail_nocontext:
+        free_cpumask_var(mm->cpu_vm_mask_var);
+
+fail_nocpumask:
         /*
          * If init_new_context() failed, we cannot use mmput() to free the mm
          * because it calls destroy_context()
diff --git a/mm/init-mm.c b/mm/init-mm.c
index 1d29cdfe8ebb..4019979b2637 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -21,6 +21,5 @@ struct mm_struct init_mm = {
         .mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
-        .cpu_vm_mask    = CPU_MASK_ALL,
         INIT_MM_CONTEXT(init_mm)
 };